Known containers for dangerous environments according to the IIC standard comprise a base and one or more side walls joined to the base, so as to define an upper opening which can be closed by a cover. The side walls are generally curved, so that it is hard to make lateral holes for the connection of the electric and/or electronic devices arranged in the container. Furthermore, the extension of the upper opening is smaller than the extension of the base, so that it is difficult to carry out the container in a single piece. For allowing the use in dangerous environments, the cover must ensure a particular seal, which is generally obtained with a threaded circular upper opening and a corresponding threaded cylindrical cover, which cause an increase of the manufacturing complexity of the container. Furthermore the threaded cover must rotate for closing the container, so that it is difficult or impossible to pass electric cables through the cover.
For overcoming said problem, US 2005/029881 and WO 00/62366 disclose a container comprising an upper opening surrounded by a first perforated flange and a cover provided with a second perforated flange for fastening these flanges by means of screws, wherein the base, the side walls and the first flange are made of a single metal piece.
U.S. Pat. No. 4,696,412 discloses a cover which is hinged to a container and is provided with a perimetric frame suitable for penetrating into the upper opening of the container and being coupled with the upper portion of the inner surfaces of the side walls. However, said frame ensures a relatively low seal, since it must be inclined and/or must have a reduced thickness, otherwise it would interfere with the upper edge of the container during the rotation by means of the hinges, thereby preventing the closing of the cover.
US 2008/237252 discloses safety hinges which allow a rotating and translatory movement of a cover with respect to a container for preventing the accidental crushing of fingers arranged between the cover and the container.